Method of and apparatus for driving a tunnel through and supporting earth structure



June 30, 1964 M. F. KEMPER 3,138,933

METHOD OF AND APPARATUS FOR DRIVING A TUNNEL THROUGH AND SUPPORTINGEARTH STRUCTURE Filed Aug. 19, 1957 6 Sheets-Sheet 1 \J s i l@ N N E QLO' AI w l i 1 N Q m Q u l N. a a

l INVENTOR.

n w w l n Mina/:a cfr/Vie f/Mare j 632g@ @W June 30, 1964 M. F. KEMPER3,138,933

METHOD OF` AND APPARATUS FDR DRIVING A TUNNEL THROUGH AND SUPPORTINGEARTH STRUCTURE Filed Aug. 19, 1957 6 Sheets-Sheet 2 S inve/VIM June 30,1964 M. F. KEMPER METHOD OP AND APPARATUS FOR DRIVING A TUNNE THROUGHAND SUPPORTING EARTH STRUCTURE 6 Sheets-Sheet 3 Filed Aug. 19, 1957INVENTOR.

June 30, 1964 M. F. KEMPl-:R 3,138,933

. METHOD OF AND APPARATUS FOR DRIVTNG A TUNNEL THROUGH AND SUPPORTINGEARTH STRUCTURE Filed Aug. 19, 1957 6 Sheets-Sheet 4 @aww June 30, 1964M F. KEMPER 3,138,933

METHOD OF AND APRARATUS FOR DRIVING A TUNNEL THROUGH AND SUPPORTINGEARTH STRUCTURE Filed Aug. 19, 1957 6 Sheets-Sheet 5 .62j www inne/V544M. F. KEMPER APPARA June 30, 1964 3,138,933 METHOD oF AND TUS FOR'DRIVING A TUNNEL RTING EARTH STRUCTURE THROUGH AND SUPPO 6 Sheets-Sheet6 Filed Aug. 19, 1957 faj INVENTOR.

United States Patent O 3,13S,933 METHD @E AND APPARATUS FR DRIVING ATUNNEL THRUUGH AND SUPPRTING EARTH STRUCTURE Maxwell Fisher Kemper, 3701Overland, Los Angeles, Calif. Filed Aug. 19,1957, Ser. No. 678,993 16Claims. (Cl. 61-85) The present invention relates to a novel method ofand an improved apparatus for driving a tunnel through earth formation,While supporting the overburden to prevent cave-in thereof.

Heretofore, it has been the practice to dig a tunnel through certainearth structures and to pour in the tunnel a concrete conduit such asmight be employed for sewer or storm drainage. Conventionally suchtunnels have been produced by successively supporting arched orhorseshoe-shaped H beams or steel supports in spaced relationlongitudinally of the tunnel as the tunnel progresses. As each beam isdisposed in position and so supported, lengths of plank or spiling aredriven into the face of the tunnel with sledge hammers. Obviously, thisrequires a great deal of manpower, and progress of such tunnels iscomparatively slow. Moreover, particularly when digging a tunnel throughsandy soil, driving of the spiling into the sand loosens this sand, andcrevices or apertures frequently are left between adjacent spilings sothat sand can commence to flow therethrough. While a small flow of sandthrough the supporting structure is not too signiiicant, such a iiowover a protracted period of time forms a substantial cavity in the earthstructure above the tunnel, so that cave-ins in such a cavity arelikely, thus possibly imposing upon the arched supports and spilings,sudden loads of substantial weight. Therefore, traditionally the archedsupports and the spiling have been rather massive in order to supportthe loads to which they are subjected.

Despite the high cost and risks involved in digging a tunnel as justdescribed, this has been the practice for many years in those instancesWhere a horseshoe crosssectional configuration is necessary from thestandpoint of structural strength, ln those instances where thestructural rigidity of the generallyy horseshoe cross-section is notnecessary, annular tunnels have been dug by forcing into the face of thetunnel a cylindrical shell which enables erection of an annularsupportingy structure within the cylindrical shell. While suchcylindrical shells have afforded certain advantages, their use has alsobeen accompanied by certain disadvantages. One of the primarydisadvantages of a cylindrical shell as aforementioned, is the lack ofdirectional control which has been a characteristic of all such shellsheretofore known.

Prior to the present invention, the conventional spiling drivingtechnique has `traditionally been employed where the horseshoe typetunnel was required. This has been necessitated by the fact that Whilethe lower side of a cylindrical shell as aforementioned affords asupporting base upon which the shell rests, a shell has not beenemployed in a horseshoe form for the lack of appropriate supportingmeans for the base of the shell.

A primary object of the present invention, accordingly, is to provide anovel method of driving a tunnel of horseshoe cross-section, this methodcontemplating the use of a shell of generally horseshoe cross-sectionadapted to be driven forcefully into the face of a tunnel as the tunnelprogresses so as to enable erection of suitable supporting structurewithin the protective cover of the shell.

Another object of the invention is to provide novel apparatus includingan elongated shell adapted to be driven into a tunnel face so as tosupport the overburden of earth and including `novel means torsupporting the 3,l38,933 Patented .lune 30, 1964 ice shell so that theoverburden o' earth does not force the sides of the shell down into theearth as the shell advarices.

A further object is to provide an improved method of driving a tunnelwhich includes driving a generally horseshoe-shaped elongated shieldinto the earth to permit removal of the earth at the tunnel face,assembling supporting arches or braces within the confines of theshield, installing lagging between successive arches under theprotection of the shield, jacking up the arches to press the lagginginto tightening conformity with the inner surface of the shield,advancing the shield further into the tunnel face while retaining theface of the tunnel against cave-in, and successively uncovering thearched and lagged tunnel-forming sections.

It should be understood that the tunnels herein referred to may be minetunnels, in which case the horseshoe supporting structure willconstitute the nished tunnel. On the other hand, however, if the tunnelis for the purpose of drainage or sewage conduction, then thehorseshoe-shaped structure previously referred to will be employed asthe outer form in the construction of a concrete conduit, as will becomemore apparent as the description progresses.

A further object of the invention is to provide a method of driving atunnel wherein a generally horseshoe-shaped shield is driven into thetunnel face and as the shield is advanced periodically, arched H beamsor steels are supported within the shield, these beams or arches beingadapted to receive and support lagging or lengths of planking which isclapped or rabbeted at its opposite ends so as to overlie the adjacentarches or beams and in the final assembly ali`ord longitudinal strengthto the tunnel. ln accordance with the invention, the lagging is engagedwith a beam at one end which is pressed tightly against the lagging ofthe preceding tunnel section and the lagging being installed in the newsection is clapped or rabbeted deeper at this end than at the oppositeend of the lagging which is engaged with an arch or beam which iscomparatively loosely disposed in place but which is jacked up tightlywith respect to the overlying shield subsequent to the installation of afull set of lagging members.

Yet another object is to provide a method as aforesaid, wherein chocksor wedges are driven between foot plates on the ends of the l-l beamsand a plank or other foundation member disposed in engagement with theearth. This is done before the jacks are released so that the `H beam ismaintained in place. An important result of this chocking arrangement isthe fact that the H beam supports the trailing portion of the shield,and in the absence of a lirm footing the H beam will permit sagging ofsuch trailing shield portion and erratic shield movement.

A further object is to provide novel apparatus which is eminently suitedto the performance of the method previously referred to and in thisconnection such apparatus preferably provides means for shiftablysupporting the U or horseshoe-shaped shield, such supporting meansincluding what will be generally referred to in this application as aneedle beam and means for supporting a needle beam. This needle beamsupport comprises a structural member adapted for relative axialmovement with respect to the shield whereby when the needle beam is heldstationary in supporting relation to the shield, the shield may beshifted axially so as to advance into the tunnel face. As each newtunnel section is erected, an auxiliary support is employed for theneedle beam while the needle beam and its main support are adjusted topermit further advancing of the shield with respect to the main support.In this connection, the needle beam support comprises an invertedU-shaped frame or arch disposed transversely of the tunnel and havingjacks in its opposite sides adapted to engage the floor of the tunnel soas to exert upward pressure upon the shield to prevent diving of theshield as it progresses into the tunnel face. As each new tunnel sectionis constructed and preparations are made for advancing the shield forthe erection of a succeeding tunnel section, the auxiliary needle beamsupport is employed to enable retraction of the jacks of the main needlebeam support whereupon the main needle beam support may be shiftedaxially with respect to the shield t a new supporting position and thejacks again put into use.

Another object of the invention is to provide novel hydraulicallyoperated means for positively forcing a shield into the tunnel face.Such means comprising a plurality of hydraulically operated ramsdisposed in spaced relation about the shield and adapted upon thepumping of fluid therein to positively force the shield ahead. Inaccordance with one of the salient features of the invention, thesehydraulic rams are supplied with uid from a positive displacement pumpof the type which will displace equal amounts of hydraulic fluid to eachof the respective shield driving rams. In order to effect directionalcontrol of the shield, the hydraulic operating system for the rams ispreferably provided with means under the control of appropriate valvemechanism for selectively forcing a greater volume of uid into one ormore selected ram cylinders, thus to cause extension of said selectedram or rams a greater distance than the other rams, thus causing theshield to be forced to turn in a given direction, depending upon whichof the rams is furthest extended.

Broadly, then, an object is to provide means for digging a tunnelincluding a shield, means for exerting uniform pressure at one end ofthe shield, preferably at spaced points thereabout, and means forexerting additional pressure at a selected point or points for effectingdirectional control of the shield.

And yet another object of the invention is to provide a novel tunneldriving shield as aforesaid which is equipped with air operatedbreastboard rams which are adapted to be projected longitudinally of thetunnel and to support breastboarding against the tunnel face.breastboard rams are air operated, they will in effect resiliently biasthe breastboarding against the tunnel face and will permit axialmovement of the shell into the tunnel face as the breastboard rams areforced back into their power cylinders, depending upon the contour ofthe face of the tunnel. In this way, cavein of the tunnel face iseliminated.

In accordance with the preceding objectives, it is a further object toprovide a method and apparatus as aforesaid which enables the dirt orearth removed from the tunnel face to be scooped up and loaded by an airoperated or otherwise powered so-called mucker'which is a front-loading,overhead-unloading type of machine, conventionally employed in thedigging of tunnels, and which is adapted to dump successive scoop loadsof earth onto a conveyor which may either carry the earth all the way tothe tunnel mouth or may transfer the earth to a mine train rearwardly ofthe tunnel digging apparatus.

The novel method and apparatus hereof are possessed of other advantagesand novel features which will hereinafter be more particularly pointedout, or will become apparent to those skilled in the art, and the novelfeatures of the invention will be dened in the appended claims.

In the accompanying drawings:

FIG. 1 is a longitudinal sectional View taken through a tunnel drivingapparatus which is made in accordance with the invention, and which isexemplary of apparatus ideally suited to the performance of the presentmethod, the shield and the needle beam support being in the positionswith respect to the needle beam which they would normally be in uponcompletion of a tunnel section and prior to forcing of the shieldforwardly into the tunnel face.

Since these Y FIG. 2 is similar to FIG. 1 but showing the shield in anextended position and showing the auxiliary needle beam support in aground-engaging, needle beam-supporting position and the main needlebeam supporting jacks retracted to enable the main needle beam supportto be advanced to a new position with respect to the needle beam, thepistons of the shield advancing rams being shown in broken lines in afully extended position.

FIG. 3 is an elevational view of the tunnel driving apparatus of FIGS. land 2;

FIG. 4 is a transverse sectional View as taken substantially on the line4 4 of FIG. 1;

FIG. 5 is an enlarged fragmentary detail view partly 1n elevation andpartly in section showing the needle beam and the main needle beamsupport and the shiftable connection between these elements;

FIG. 6 is a view in section as taken substantially on the line 6 6 ofFIG. 5;

FIG. 7 is an enlarged fragmentary detail view in section takentransversely of the tunnel driving apparatus substantially on the line 77 of FIG. 2 and more particularly showing the method of jacking up thesuccessive hoseshoe shaped or arched supporting H-beams or steels intotight engagement with the shield prior to shifting the position of theneedle beam support and further driving of the shield;

FIG. 7a is a fragmentary elevational view on an enenlarged scale, astaken on the line 7a 7a. of FIG. 7.

FIG. 8 is an enlarged fragmentary detail view in section as taken on theline 8 8 of FIG. 7 and more particularly showing the novel method ofdapping or rabbeting the lagging planks to enable their insertionbetween adjacent arched steels or beams; and

FIG. 9 is a diagrammatic view of the hydraulic and pneumatic system foroperating the various instrumentalities of the novel apparatus hereof.

Like reference characters in the several figures of the drawings and inthe following detailed description, designate corresponding parts.

Referring particularly to FIG. 1, novel apparatus is shown foraccomplishing the method of the present invention.

In accordance with the invention, the apparatus comprises a generallyU-shaped shield S, having an outer skin plate 1 extending rearwardly ofthe body of the shield so as to provide an elongated skirt, and an innerplate 2, which are suitably reinforced and interconnected withstructural members 3. At its forward extremity, the shield S is providedwith a cutting edge 4. The inner wall of the shield S is provided withan angularly disposed forward section 5 providing somewhat of a plainsurface. The shield S has an arcuate upper leading edge 6 which isdisposed substantially transversely of the tunnel and with a pair ofdownwardly extending sections 7 constituting side Walls of the shield,which side walls recede toward the rear of the shield from the toptowards the bottom thereof. Centrally mounted and longitudinallydisposed within and secured to the shield S is a needle beam N whichwill be more particularly described hereinafter. The needle beam isprovided with a pair of needle beam supports, namely a main support Awhich is generally arched or U-shaped in form and which is adapted to beshifted with relation to the needle beam N relative thereto; and anauxiliary support B which is pivotally mounted on the beam as at 8 andwhich is adapted to be moved from an inoperative position parallelingthe needle beam as shown in FIG. 1, to an operative position in groundengaging needle beam supporting relation as shown in FIG. 2.

In the use of the apparatus, an air or other power operatedfront-loading overhead-unloading machine or mucker M is adapted to movebetween the opposite laterally spaced sides of the main needle beamsupport A so as to scoop up earth and transfer the same overhead to aconveyor assembly X as shown in FIG. 1. The conveyor assemblies areconventional elements and need not be further described since theiroperation is well known to those skilled in the art and they arecommonly employed in the tunnelling held.

As previously mentioned, the needle beam support A and the needle beam Nare shiftable with relation to one another and, as more particularlyseen in FIGS. and 6, the needle beam N is preferably composed of a pairof U-shaped structural members 1i), 1G disposed back to back in spacedrelation and interconnected at their extremities by transverselyextended plates 11, 11. At its upper side, the needle beam N is boltedas by bolts 12 to the inner plate 2 of the shield S and at its base theneedle beam N has welded or otherwise suitably secured thereto a pair oflongitudinally extended rails 13. The needle beam support A has securedto its upper end and substantially at its midpoint, a pair of laterallyspaced upstanding roller supports 14, 14 in which are suitablyjournalled a pair of rollers 15, 15 which extend transversely of theneedle beam and are in rolling contact with the rails 13 previouslyreferred to. In addition, the roller supports 14 have a pair of upwardlyprojecting bearing blocks 16, 16 thereon which are adapted to rotatablysupport a pair of rollers 17, 17 which are rotatably mounted on axesparallel to the axes of the rollers 15, 15 and to rollingly engage withthe lower flanges 1S, 18 of the U- shaped structural members 10, 10.Furthermore, the roller supports 14 are provided with opposed pairs ofoutstanding ears 19, 19 and 20, 20 in which are respectively mounted apair of rollers 21 and 22 which latter rollers are disposed on axesnormal to the axes of the rollers 15 and 17. The rollers 21 and 22 areadapted to rollingly engage the outside edges of the rails 13, 13.Accordingly, it will be noted that the rollers 15, 17, 2l and 22completely support the needle beam support A upon the needle beam forrelative movement of these parts.

In order to effect such relative movement of the needle beam support Awith relation to the needle beam N, a pair of fluid pressure operatedrams 23 are connected at one end to the needle beam N at opposite sidesof the latter as at 24, and each ram 23 includes an operating rod 25which is connected to an upstanding bracket 26 on the needle beamsupport A.

The rams 23 will act to shift the needle beam support A to the left asseen in FIG. 1 with respect to the needle beam and the shell andtherefore means are also provided for limiting such movement. Such meansis preferably in the form of a pair of rods 23 which extend rearwardlyof the needle beam astraddle auxiliary needle beam support B, and whichare interconnected as by a yoke member 29 to a come-along 30. Thecome-along being connected as at 31 to a pair of rods designated 32which are adapted to be connected at their end to any suitable ixedsupport.

As is best seen in FIGS. 3 and 4, the needle beam support A is providedin its opposite sides with a pair of fluid pressure operated jacks 33and with telescopic legs 34 adapted to engage the ground at the oor ofthe tunnel upon expansion of the rams 33 so as to jack up the needlebeam N and the shield S. The jacks 33 also serve to raise the legs 34 asshown in FIG. 2, so that the needle beam N may be supported on theauxiliary needle beam support B to a new supporting position. Theauxiliary needle beam support B is also provided with a jack member 35which is shown as being of the screw type but which, of course, withoutdeparting from the invention, may also be hydraulically operated. In anyevent, however, the jack 35 may be manipulated to exert upward pressureupon the shield S to support the same as the legs or jacks 34 of themain needle beam support A are elevated and the support A is shifted toa new position.

In order to facilitate movement of the auxiliary needle beam support Bfrom the supporting position shown in FIG. 2 to a raised inoperativeposition as shown in FIG. l, a chain 36 is preferably connected to theneedle 5:5 beam support B and is operatively engaged with driving meanspowered by a motor 37 of the air or hydraulically driven type which issecured at the rear extremity of the needle beam N, and which is adaptedto feed the chain 36 through the driving means so as to swing the latterabout the pivot 8 to the inoperative position aforesaid.

In order to advance the shield S from the position shown in FIG. l tothe one shown in FIG. 2, the shield has mounted therein a series ofsubstantially equidistantly spaced latitudinally extended rams or fluidpressure operated actuator cylinders as are best seen in FIG. 4, thesecylinders being designated respectively 38, 39, 40, 41, 4t2 and 43. Thepistons of these actuator devices are adapted to be backed up by a meanswhich will hereinafter be more particularly described, while thecylinders of said devices are rigidly connected to the shield S, so thatupon the admission of fluid from a source of supply, the cylinders willbe shifted axially with respect to the pistons and consequently theshield S will be urged axially into the face of the tunnel. The motivefluid for these actuator cylinders 38 through 43 is preferably ahydraulic uid supplied thereto from a reservoir R consisting of acylindrical tank recessed within the needle beam N, as is best seen inFIGS. 4 and 6.

As the shield S progresses into the tunnel face, the latter wouldnormally tend to cave-in, and accordingly, in conformity with one of thesalient features of the invention, the shield preferably carries aplurality of breastboard retaining cylinders 44, 45, 46 and 47. Thecylinders 44 and 47 are, as is best seen in FIG. 3, preferably disposedsubstantially at the spring line of the tunnel, while the cylinders 45and 46 are disposed adjacent the top of the shield on opposite sides ofthe vertical center of the latter. Each of the breastboard supportingactuator cylinder devices is provided at the free end of its piston witha generally L-shaped supporting bracket 48 adapted to support thereon intransversely extending relation, upper and lower breastboards 49 andSil', respectively, Which are adapted to engage the tunnel face and toprevent substantial cave-in thereof. In addition, a suitable number ofvertically arranged planks as indicated at 51 may, if desired, beinterposed between the breastboard 50 and the tunnel face, so as tofurther retain the tunnel face against collapse. As will hereinaftermore fully appear, the breastboard actuator cylinders 44 through 47 arepreferably air operated so that the shield S, upon which the cylindersof the breastboard actuator devices are carried, advances into thetunnel face, the respective pistons may be forced back into thecylinders thus compressing the air and thereby tending to yieldably beretained against the tunnel face by virtue of the compressed air withinthe actuators.

In operation in accordance with the method of the present invention, andassuming the apparatus to be as shown in FIG. l, fluid is admitted tothe shield driving hydraulic actuator devices 38 through 43 from thereservoir R so as to force the shield S axially into the face of thetunnel while the breastboard supporting actuator devices 44 through 47serve to resiliently retain the breastboard arrangement against thetunnel face to prevent substantial cave-in. When the shield hasprogressed to the point shown in FIG. 2 with the pistons of the actuatordevices 3S through 43 substantially fully extended as shown in brokenlines in this view, each of the successive horseshoe shaped supportingmeans C shown in FIGS. l and 2 are installed in the same manner as nowto be described, with particular reference to FIG. 7, and FIG. 8.

The arched H beam or steel half sections 50 and 51 would ordinarily bedispose in an out of the way position adjacent to the conveyor X so thatwhen the pistons of the actuator devices 3S through 43 have beenretracted to the positions shown in full lines in FIG. 2, the respectivehalf sections 5t) and 51 may be elevated into an initial position andbolted together at the midpoint of the beam as at 52. A pair of jacks 53and 54 are respectively engaged with jack-engaging projections 55 and 56on the arched H beam half sections 50 and 51, and the arched beam C isthus held in its initial position, whereupon, commencing at the bottomat each side of the arched beam support, planks or lagging generallydesignated 57 are set into place longitudinally of the tunnel so as tospan the space between the preceding arched support or rib C and the onepresently being installed. In order to facilitate installation oflagging in the crown of the tunnel, arms 27 are preferably supported atone end upon the legs of the needle beam support A and extendlongitudinally of the tunnel. These arms afford supporting means onwhich a platform or scaffolding may be disposed.

As is best seen in FIG. 8, the opposite ends of each lagging or plank 57are notched or dapped with the end of each lagging or plank which isfirst to be inserted, rabbeted or dapped as at 58 to a greater extentthan the opposite end of the lagging or planks as at 59. Since thepreviously installed arched H beam or rib C is firmly pressed andsecured in position against the lagging which in turn is pressed againstthe outer skin 1 of the shield S. This differential dapping of the endsof the lagging 57 facilitates insertion of the deeper dapped end 58 intothe space between the last mentioned rib C and the shield S. As isclearly illustrated in FIG. 8, by virtue of this arrangement, the archedwall formed by the lagging is not in uniform frictional engagement withthe outer skin 1 of the shield S, thus substantially reducing the forcerequired to shift the shield.

Following the insertion of the lagging 57, the jacks 53 and S4 areemployed to jack the arched beam C into firm engagement with the ends 59of the lagging. Chocks or wedges 60 are driven between foot plates 61 atthe lower extremity of the respective half sections 50 and 51 of thebeams C and a plank 60a which is disposed in engagement with the groundand affords adequate supporting area for the ribs C, whereby they willbe tightly held in place by the chocks 60. This will preclude the shieldS from sagging at the rear during forward movement thereof. It should benoted that prior to final tightening of the arched beam C beinginstalled, a series of tie bolts 62 are extended between adjacent Hbeams or ribs C so as to rigidly tie the same together in uniformlyspaced relation, the tie bolts 62 being preferably substantiallyequidistantly spaced about the extent of the tunnel section. Inaddition, closely adjacent to each of the tie bolts 62, a plurality ofcollar braces 63 are installed, these collar braces being adapted to fitwithin the flanges of the H beam as shown in FIG. 8 at the respectiveopposite ends of the collar braces. As is best seen in FIGS. 1 and 2,the collar braces 63 constitute an elongated reinforcing member backingup the respective shield driving actuating devices 38 through 43, thepistons of which, as previously mentioned, are backed up against thelast installed arched beam support C as shown in FIGS. l,

v2 and s.

Following final tightening up of the arched beam supports C justinstalled as shown in FIG. 7, the auxiliary needle beam support B willbe lowered to the position shown in FIG. 2 and the jack 35 actuated toexert upward force upon the needle beam N, thus relieving the load uponthe main needle beam support A. Thereupon, the telescoping legs 34 ofthe needle beam support A are elevated by the fluid pressure operatedjacks 33 therein, as also shown in FIG. 2. Upon such elevation of thelegs 34, the actuator devices 23 may be pressurized to shift the needlebeam support A to the position shown in FIG. l. However, in order toeffect such movement of the needle beam A, tension on the yoke retainingmeans 28 must be relieved through the action of the comealong 30 andafter the repositioning of the needle beam support A has been effected,the comealong may be employed to retention the yoked links 28 so as toprevent further forward movement of the needle beam support A.

At this time, the telescopic legs are jacked back down into engagementwith the earth surface and the jack is relieved of supporting engagementwith the ground and the iiuid operated motor 37 may then be controlledto pull the chain 36 rearwardly so as to elevate the auxiliary needlebeam support to the position shown in FIG. 1.

Referring to FIG. 4, at the lower left hand side of the assembly, thereis shown a control panel D, and all of the foregoing operations arepreferably effected manually from this control panel which is part of ahousing containing suitable control valves and operating mechanism whichwill hereinafter be more particularly described for controlling theoperation of the fluid pressure circuitry shown diagrammatically in FIG.9.

Passing now to FIG. 9, the jacks 33, 33 of the main needle beam supportA are so designated in the diagram. Likewise the breastboard cylinders44 through 47 are so designated, as are the needle beam support shiftingactuators 23 and the shield shifting actuator devices 38, 39, 40, 41, 42and 43. The reservoir R in the needle beam N is shown in the diagramalso.

Diagrammatically illustrated in FIG. 9, is a positive displacement pumpP of the radial reciprocating piston or other appropriate type which isdriven by a motor M and which is capable of pumping from the reservoir Rthrough a line R' upon each revolution of the pump, equal volumes ofhydraulic fluid through lines 38a, 39a, 40a, 41a, 42a and 43a, theselines respectively leading to the actuator cylinder devices, 38 through43 respectively through branch lines 38b, 39b, 4Gb, 41b, 42h and 4317,for forcing the shield S axially. Each of the lines 38a through 43a isrespectively provided with a pressure gauge as generally indicated atand in addition, if desired, each of these lines is also provided with abranch leading to a check valve 62', these branch lines being manifoldedas at 63' to a relief valve 64 of an appropriate type. Branch lines 38hthrough 43h are also provided with check valves 65 and throttle valves66, and are manifolded through line 67 to a supply line 68 which is inturn connected to a reservoir R through a line 69 which is preferablyprovided with a check valve 70 and preferably a filter '70. Lines 38hthrough 4311 are also interconnected with exhaust lines 71 shown inbroken lines in FIG. 9, these exhaust lines being manifolded throughexhaust line 72 to a return line 73 leading to the reservoir through afour-way air operated valve 74, the operation of which will behereinafter more particularly described. Preferably interposed in theline 73 is a check valve 75.

In order to combine the compressiveness of air with the positivedisplacement characteristics of liquid or oil, the system shown in FIG.9 is preferably a combination air and oil system, and as shown in thisview, the reservoir R is partially filled with oil and partially filledwith air. Air is supplied to the reservoir through a line 76 via an airoperated valve 77 from a supply line 78 which is connected to a suitablesource of air under pressure, such source may be located rearwardly ofthe structure previously described and within the tunnel as at 79. Asuitable separator or filter may be installed in the air feed line or ifdesired both of such elements may be installed therein.

It will be noted that the air motor 37 previously referred to whichserves to feed the chain 36 through a drive mechanism, as previouslydescribed, is interconnected with an air supply line such as the line76, through a branch line 8) having a control valve 81 therein forcontrolling the operation of the air motor` 37.

The air supply line 78 is connected through a conventional regulator 82,through a branch line 83 leading to a booster 84 and a line 85, with themotor M which is preferably of a known air driven type. The line 85preferably is provided with a shut-off valve as at 86. Thus, it will beseen that air under pressure admitted into the system through line '78serves to provide motive power to the motor M and also to provide asource of pressure Q for pressurizing the oil contained in the reservoirR.

In addition, there is branch line 87 connected to the air line 78 whichis adapted to be selectively connected through a manually operatedfour-way valve 89, selectively, with air operated valve 74 through 'aline 90, or with air operated valve 77 through a line 91. Thus, thevalve 89 will serve the dual purpose of controlling the admission of airunder pressure into the reservoir and controlling the return flow offluid from the shield rams 38 through d3, through the return lines 71,manifold 72 and line 73 in which valve 7d is installed. Valve 7/-1serves a further function with respect to controlling the selectiveinjection of additional volumes of fluid into selected rams of theseries of shield actuating devices 38 through 43. In this connection, itwill be noted that an air motor 92 is adapted to be driven by airsupplied through line 93 which is interconnected between the motor 92and the supply line 78, the line 93 being preferably provided with alubricator as at L, a gauge 9d and having therein a regulator 95 forcontrolling the operation of the air motor 92. The motor 92 drives abooster pump 96 having an inlet line 97 interconnected through lines 73,68 and 69 as well as through check Valve 7l) with the oil in thereservoir R. The booster pump 16 also has an outlet line 93 which isadapted to he selectively placed into communication with a line 99through the air operated valve '74 just referred to above, when the airoperated valve 74.1 is in one position responsive to appropriatemanipulation of manually controlled valve S9. In addition, the line 97may be provided With an accumulator 11)@ for maintaining a constantpressure upon the iluid in the line 99 when the valve '7d establishescommunication with the latter line and line 97.

Accumulator 11B@ is adapted to maintain a pressure greater than thepressure in fluid lines 38h through 431i, as may be determined by thegauges 6@ previously described and a gauge 1111 in line 99 which isconnected to a series of lines 38e, 39C, 411C, 41C, 42C, and 413e whichare respectively connected to the lines 35h through 3b. The lines 38Cthrough 43C, respectively, are preferably provided with a check valve ascollectively designated at 102, as well as with a manually controlledshut-olf valve, such shut-off valves being collectively designated at103. As the result of this arrangement, it will be noted that under theselective control of valves 163, additional oil under pressure may bedirected to the respective shield driving rams 38 through 43 so that anyof these rams either singly or in combination may be provided with extralluid to force such rams to expand somewhat further than the other rams.Therefore, in the event that during a tunnel digging operation, itshould appear that the shield is beginning to veer olf course,directional control of the stueld may be eifected through selectiveadvancement of the respective rams. In practice, a surveying instrumentsuch as a transit is employed in the tunnel to taire a sight on thedirection of travel of the shield following the installation of eachsuccessive rib or steel C. ln this manner, any deviations of the shieldduring each successive section construction, may be compensated for asthe shield progresses.

In order to retract the pistons of the rams 33 through 43 prior to theinstallation of a rib or steel C, as previously described, a line 11Mis'connected to the respective actuator devices through lines 1115, thisline 1114 also being connected through manually controlled valve S9 toline 87 previously referred to, which is in turn connected to air supplyline 73. Thus, when the manual control valve 39 is shifted from a shieldshifting position to a ram retracting position, the rams will beretracted.

It is desired that the breastboard actuator cylinders be supplied withair to resiliently bias the breastboards against the tunnel face, andaccordingly, these cylinders are also connected to the air supply line78. The lower breastboard cylinders 44 and'd are interconnected to thelines 7 S through a branch line 1115" having a lubricator therein,

the line 1115 being connected through a line 106 via a pair of manuallycontrolled four-Way valves 107 and 108. Upon shifting of these valves107 in opposite directions, it will selectively effect communicationbetween the line and the opposite sides of the piston of the ram of theactuator cylinder del with an exhaust port, as Will be well recognizedby those skilled in the art. Valve 108 functions in the same manner asvalve 1117 so as to control the projection and retraction of the pistonof actuator cylinder 45. The upper breastboard cylinders 46 and 47 areconnected to air supply line 7 3 through a line 109 via aline 111B whichfeeds through a pair of manually controlled four-Way valves 111 and 112for controlling the projection and retraction of the cylinders 46 and 47in the same manner as the pistons of cylinders 44 and 45 are actuatedunder the control of valves 1117 and 108.

As has been previously pointed out, prior to shifting the needle beamsupporting arch A, the telescopic legs 34 thereof are retracted by theduid pressure operated jacks 33, as shown in FlG. 2 of the drawings. Asshown in FIG. 9, the system for operating the actuator devices 33 isValso a combined air and oil system in its preferred embodiment andpreferably includes a reservoir 113, the air being supplied to thereservoir through a line 114 which is connected to a line 115 leadingfrom the air suply line 78 previously referred to through a manuallycontrolled valve 116. The manually controlled valve 116 also controlsthe connection of the fluid supply line 78 to a line 117 which isconnected through a check valve 118 to a line 119 Which isinterconnected with both of the actuators 33 at the outer side of thepiston so as to effect retraction of the piston within the cylinder 33.Oil is supplied under pressure imposed thereon by the air in the upperpart of the reservoir 113 through a lter 120, a check valve 121 and aline 122 which is interconnected with the actuator cylinders 33 througha pair of shut-off valves 123, 123, and a pair of throttle valves 124.Inasmuch as the air pressure which causes expansion of the rams 33through the oil in the system is compressible, Whereas rigid support ofthe needle beam support A is desired during operation, the rams 33 areinitially expanded by the air pressure and the valves 123 are thenclosed off, thus trapping iluid in the rams 33. In order to furtherexpand the rams, each branch of the hydraulic circuit for operating therams 33 is provided with a manually or otherwise operated high pressurepump 125 which is connected to the actuator cylinders 33 through a checkvalve 126 and thence through the throttle valves 12d at the closed olfside of the respective shut-olf valves 123. Accordingly, with the Valves123 closed, the pumps 125 may be manually operated, or if desired suchpumps may be power operated; but in any event the function of the pumpsis to inject additional volumes of hydraulic fluid under high pressureinto the rams 33.

During elevation of the legs 34, which may be simply elfected merely byopening shut-off valves 123 and operating manually controlled valve 116to permit the passage of air through line 117 into line 119, any excesspressure in line 119 being bled off through a relief valve, as indicatedat 127, hydraulic liuid in the actuator cylinders 33 will, of course,pass back into the reservoir 113through a line 128 having a check valve129 therein and interconnecting liue 122 with the reservoir 113.

With the legs 3d so elevated and in accordance with the present method,the needle beam support A will then be shifted forwardly of the shieldtowards the tunnel face by the needle beam support shifting cylinders 23which, as shown in the diagram now being described, are airoperatedthrougha line 13@ which is suitably connected to the air supply systemas by connection with the line 87. The line 1319 is provided with amanually controlled fourway valve 131 which is adapted to establishcommunication between line 1311 and one side of the pistons of theactuator cylinders 23 through a line 132 and with the other side of saidpistons through a line 133. One of the latter lines leads to theexpansion side of the piston and the other of said lines leads to theretraction side of the piston. Each of the lines 132 and 133 ispreferably provided with a flow-controlling valve assembly including acheck valve 134 and a throttle valve 135, whereby movement of thepistons of these actuator cylinders 23 in opposite directions iscushioned by the action of the throttle valves 135.

It will be aparent to those skilled in the art that without departingfrom the invention, variations may be resorted to in the hydraulicsystem shown in FIG. 9.

It should now be recognized that with the apparatus hereof in thecondition shown in FIG. l, such apparatus will be operated in theperformance of the present method as follows:

Valves 123 of the needle beam jack operating system will be closed sothat fluid in the cylinders of the jacks 33 is trapped therein, but ifdesired, this tluid column in the actuators may be supplemented by theoperation of the high pressure pumps 125. The throttle 82 is thenoperated so as to effect operation of the motor M whereby pump P willsupply fluid under pressure to the respective shield rams 38 through 43,in equal volume per revolution of the pump. However, should it bedesired to correct for any deviation of the shield which may haveoccurred during prior operations, the valves 74 and 89 will bemanipulated so that the booster pump 96 will supply fluid selectivelythrough the lines 3de through 43C so as to inject additional volumes offluid into one or more selected cylinders of the cylinders 38 through43, thus effecting a steering action of the shield S as it progresses.

During progression of the shield S, air is continuously supplied throughsupply line 78 to the upper and lower breastboard cylinders throughtheir respective control valves 107, 108, 111 and 112, so as toresiliently maintain the breastboards 50 and 51 in engagement with theface of the tunnel, thus preventing undue cave-in thereof. After theshield has been fully extended so that the pistons of the shield rams 38through 43 are inthe positions shown in broken lines in FIG. 2, then thehalves of the arched H-beam or steel support C Will be bolted togetherand the rib C will be installed in position for supporting the laggingbetween it and the last installed H-beam support or steel C.

The lagging will be installed preferably working from the bottomupwardly at each side of the tunnel with the deeper dapped end of eachlagging being inserted first into engagement between the last installedH-beam support C and the skirt of the shield, the other end of thelagging then being easily slipped into position loosely lying on theH-beam support which is in the process of installation between thelatter and said shield skirt. The jacks 53 will then be employed tofirmly urge the H-beam support or rib into tight engagement with thelagging and press the lagging up against the skirt of the shield S, withthe collar braces 63 disposed between and acting as spacing means forthe previously installed H-beam support C and that being installed. Thetie rods 62 will then be tightened so that the newly installed H-beamsupport is well secured, whereupon the auxiliary needle beam support Bwill be released and swung down to the position shown in FIG. 2, theScrew jack 35 being operated to relieve the load from the main needlebeam support or arch A. The valves 123 will then be opened, and valve116 will be operated to supply air under pressure through line 117, soas to raise the legs 34 of the needle beam support A. With the legs 34so elevated, comealong 30 will be operated to relieve tension in thelinks 28, so that the arched support A is free for movement towards theface of the tunnel. Thereupon, valve 31 of the needle beam supportshifting cylinder system will be operated so as to project the pistonsfrom the cylinders of the actuator devices 23 to shift the needle beamsupport to the position shown in FIG. l.

Thereafter, line 117 will be exhausted through valve 116, and valves 123opened so as to again force the legs 34 downwardly into engagement withthe base of the tunnel. The valving for the needle beam jack operatingsystem will then be set as previously described. Air motor 37 will thenbe supplied with air through valve 31 in line 8) so as to elevate thescrew jack or auxiliary needle beam support B to the position shown inFIG. l where it will be resecured. With each new tunnel section theabove described operation is, of course, repeated.

It will now be apparent, that the present invention provides substantialimprovements in the art of digging or driving tunnels Where a protectiveshield is employed to support the overburden of earth as a permanentsupporting structure is being erected within the protection of theshield. If desired, the tunnel may be left as is, that is with the earthsupported solely by the ribs C and lagging thereon, or if desiredsuitable forms may be disposed within the frame structure to enable theinjection of hydraulic concrete within the space between the form andthe supporting structure so as to provide a concrete conduit.

Moreover, while the specific details of the present method and apparatushave been herein shown and described, changes and alterations may beresorted to without departing from the spirit of the invention asdefined in the appended claims.

I claim:

l. The method of driving a tunnel in the earth comprising: driving ashield into the earth; removing the earth from the shield at the tunnelface; constructing a reinforcing structure within the shield whilesupporting the overlying earth on the shield; advancing the shield toexpose the reinforcing structure; supporting the overlying earth on thereinforcing structure; driving the shield with a plurality ofsubstantially identical spaced hydraulic Huid rams; and forcing equalvolumes of hydraulic fluid into each of said rams from a separate sourceof hydraulic uid under pressure for each ram.

2. The method of driving a tunnel in the earth comprising: driving ashield into the earth; removing the earth from the shield at the tunnelface; constructing a reinforcing structure within the shield whilesupporting the overlying earth on the shield; advancing the shield toexpose the reinforcing structure; supporting the overlying earth on thereinforcing structure; driving said shield with a plurality ofsubstantially identical hydraulic rams; and forcing equal volumes ofhydraulic fluid into each of said rams from a separate source underpressure for each ram while forcibly injecting an additional volume ofliuid into selected ones of said rams to effect directional control ofthe shield.

3. In a tunnel driving apparatus, a movable tunnel cutting shield; meansfor driving said shield forwardly through the earth; retaining means forsupporting the earth at the face of said tunnel, said retaining meansbeing carried by said shield and comprising earth engaging membersadjacent the front of said shield and means yieldably reactingrearwardly against said earth engaging members and forwardly againstsaid shield for maintaining pressure on said earth engaging members.

4. The method of constructing an arched tunnel reinforcing structurecomprising: erecting an arched rib support in spaced but supportingrelation to an overlying shield; erecting a second arched rib support inaligned spaced relation to the first mentioned rib, forwardly thereofand in underlying spaced relation to said shield; placing laggingbetween said ribs and said shield and spanning the space between saidribs with said lagging; jacking up said second rib to force said lagginginto tight supporting engagement with the shield; and securing saidsecond rib in place.

5. The method as dened in claim 4 comprising: dapping the opposite endsof said lagging and disposing the ends of said lagging between said ribsand said shield with a portion of said lagging between the dapped endsbetween opposed surfaces of said ribs.

6. The method as deined in claim 4 comprising: clapping said lagging atits opposite ends deeper at one end than at the other end of thelagging; and inserting the deeper dapped end of the lagging between thefirst mentioned rib and the shield and the other end of the laggingbetween the second mentioned rib and the shield.

7. The method as defined in claim 6 including: installing collar bracesbetween the two ribs; and advancing said shield with respect to thereinforcing structure to expose the latter to the overlying earth withhydraulic rams backed up against the second rib in alignment with saidcollar braces.

8. Apparatus for forming a tunnel in the earth comprising: a generallyhorseshoe-shaped elongated shield; means shiftably supporting saidshield for axial movement; and fluid pressure operated means foradvancing said shield axially; wherein said means for shiftablysupporting said shield comprises an elongated member disposedlongitudinally of and underlying said shield and secured thereto; asupporting member disposed beneath said elongated member; meansshiftably interconnecting said elongated member and said supportingmember; and a second auxiliary supporting member movably connected tosaid elongated member for selective movement into and out of supportingposition beneath said elongated member, one of said supporting membersbeing rearwardly of the other relative to the advancing end of saidshield, each of said supporting members being extensible for effectingengagement with the tunnel door.

9. Apparatus for forming a tunnel in the earth comprising: an elongatedtunnel cutting shield; means shiftably supporting said shield for axialmovement; means for advancing said shield, including a plurality ofsubstantially identical spaced hydraulic rams bearing against saidshield; and means for forcing into each of said rams equal volumes ofhydraulic uid.

10. Apparatus for forming a tunnel in the earth cornprising: anelongated shield, means shiftably supporting said shield for axialmovement including a vertically disposed member; means for advancingsaid shield, including a plurality of substantially identical spacedrams; means for forcing equal volumes of liuid under pressure to each ofsaid rams with each ram receiving its liuid from a separate source underpressure; and means for controlling the direction of movement of saidshield.

11. Apparatus as defined in claim 10, wherein said direction controllingmeans includes means for forcing additional hydraulic fluid to selectedrams.

12. A tunnel forming shield comprising: an elongated body of archedcross section; said body having an open bottom; supporting meansengageable with the iioor of a tunnel and engaged with said body forsupporting said body; said body including a needle beam carried by saidbody at the crest of the arch thereof; said supporting means comprisinga member depending from said needle beam for engaging the floor of thetunnel and in shiftably supporting engagement with said beam formovement thereon; and a second supporting member movably connected toand carried by said beam for movement into a depending position forsupporting the beam and out of beam supporting position, one of saidmembers being rearwardly of the other relative to the advancing end ofthe body.

13. A tunnel forming shield comprising: an elongated body of archedcross sections; said body having an open bottom; supporting meansengageable with the floor of a tunnel and engaged with said body forsupporting said body; said body including a needle beam carried by saidbody at the crest of the arch thereof; said supporting means comprisinga irst member depending from said needle beam; means shiftablyconnecting said member to said body including rollers coengaged withsaid needle beam and said member; and a second member pivoted to saidneedle beam for movement into and out of position to engage the lioor ofthe tunnel, one of said members being rearwardly of the other relativeto the advancing end of the body.

14. A tunnel forming shield comprising: an elongated body of archedcross section; said body having an open bottom; means engageable withthe floor of a tunnel and engaged with said body for supporting saidbody; said body including a needle beam carried by said body at thecrest of the arch thereof; said means engageable with the floor ofthetunnel comprising a member depending from said needle beam and inshiftably supporting engagement therewith; said member being disposedtransversely of the shield and having laterally spaced legs foraccommodating an earth moving machine therebetween; and a supportingmember movably connected to said needle beam and selectively engageablewith the floor of the tunnel, one of said members being rearwardly ofthe other relative to the advancing end of the body.

15. In a tunnel driving apparatus a tunnel forming shield and means fordriving said shield forwardly into the earth, said means comprising aplurality of substantially identical hydraulically operated rams bearingagainst said shield, means for supplying, from a separate source foreach ram, equal volumes of hydraulic iuid under pressure to said rams todrive said shield into the earth; and means for supplying from a sourceseparate from said iirst named sources an additional volume of hydraulicfluid to a selected ram to eiiect directional control of said shield.

16. A hydraulic pressure system as defined in claim 15, wherein themeans supplying equal volumes of hydraulic uid to said rams comprises amulti-cylinder pump; and means establishing fluid communication betweeneach of said rams and a respective one of said cylinders.

References Cited in the ile of this patent UNITED STATES PATENTS 427,339Mattson May 6, 1890 498,855 Morris June 6, 1893 810,428 Parmelee Jan.23, 1906 1,100,142 McDowell June 16,1914 1,353,274 Schluter Sept. 21,1920 1,855,466 Barber et al Apr. 26, 1932 1,896,439 Dunlop Feb. 7, 19332,139,563 Russell Dec. 6, 1938 2,264,100 Smith Nov. 25, 1941 2,328,779Bonnell Sept. 7, 1943 2,757,515 Wilbur et al Aug. 7, 1956 2,758,467Brown et al Aug. 14, 1956 2,997,853 Kemper Aug. 29, 1961 FOREIGN PATENTS94,217 Germany 1897 311,303 Germany Mar. 12, 1919 768,071 France May 7,1934 910,770 Germany May 6, 1954 719,170 Great Britain Nov. 24, 1954185,332 Austria Apr. 25, 1956

1. THE METHOD OF DRIVING A TUNNEL IN THE EARTH COMPRISING: DRIVING ASHIELD INTO THE EARTH; REMOVING THE EARTH FROM THE SHIELD AT THE TUNNELFACE; CONSTRUCTING A REINFORCING STRUCTURE WITHIN THE SHIELD WHILESUPPORTING THE OVERLYING EARTH ON THE SHIELD; ADVANCING THE SHIELD TOEXPOSE THE REINFORCING STRUCTURE; SUPPORTING THE OVERLYING EARTH ON THEREINFORCING STRUCTURE; DRIVING THE SHIELD WITH A PLURALITY OFSUBSTANTIALLY IDENTICAL SPACED HYDRAULIC FLUID RAMS; AND FORCING EQUALVOLUMES OF HYDRAULIC FLUID INTO EACH OF SAID RAMS FROM A SEPARATE SOURCEOF HYDRAULIC FLUID UNDER PRESSURE FOR EACH RAM.